Dexter Master Cylinder Assembly, 1.25 Inch Bore, for Model 60 Actuator and Aero 7500 Actuator

This is the Dexter master cylinder assembly (part number 068-085-00), a 1.25 inch bore drum-brake master cylinder built for use with the Model 60 actuator and the Aero 7500 actuator. The master cylinder is the core hydraulic component inside a surge brake actuator: when the tow vehicle brakes and the actuator compresses, this cylinder converts that mechanical force into hydraulic pressure, sending fluid through the brake lines to apply the trailer's drum brakes. Because it is sized specifically to the Model 60 and Aero 7500 actuator bodies, it is intended as a direct replacement inside those units rather than a universal part.

Ordering the correct bore size matters for proper brake feel and stopping power, and this unit is specified at a 1.25 inch bore to match its intended actuators. It ships as the master cylinder only, for installation into an existing Model 60 or Aero 7500 actuator housing during a rebuild or repair.

Specifications

• Brand: Dexter
• Manufacturer Part Number: 068-085-00
• Product Type: Master Cylinder
• Bore Size: 1.25 inches
• Compatible Actuators: Model 60 Actuator, Aero 7500 Actuator
• Brake Type: Drum brake
• Weight: 3.4 pounds

Fitment

• Model 60 Actuator
• Aero 7500 Actuator

Frequently Asked Questions

What actuators does the Dexter 068-085-00 master cylinder fit? The Dexter 068-085-00 master cylinder is built for use with the Model 60 actuator and the Aero 7500 actuator.

What is the bore size of this master cylinder? This Dexter master cylinder has a 1.25 inch bore.

Does this include the full actuator assembly? No, part number 068-085-00 is the master cylinder only, intended for installation inside an existing Model 60 or Aero 7500 actuator housing.

What type of brakes does this master cylinder work with? It is a drum brake master cylinder, designed to generate hydraulic pressure for a trailer's drum brake system.

How much does the Dexter 068-085-00 master cylinder weigh? It weighs 3.4 pounds.

Will this master cylinder work with any surge actuator? No, the 068-085-00 is sized specifically for the Model 60 and Aero 7500 actuators, so it should be matched to one of those units rather than used as a universal fit.

Why would I need to replace the master cylinder in my actuator? A worn or leaking master cylinder inside a Model 60 or Aero 7500 actuator can cause soft brakes or fluid loss, and replacing it with the Dexter 068-085-00 restores proper hydraulic function.

Is this a genuine Dexter part? Yes, part number 068-085-00 is a Dexter-branded master cylinder assembly.

Does the bore size affect braking performance? Yes, bore size determines the hydraulic pressure and fluid volume the master cylinder produces, which is why the 1.25 inch bore of the 068-085-00 should match the actuator it is installed in.

Can I install this myself or does it require a mechanic? Installing the Dexter 068-085-00 master cylinder involves opening the actuator housing and connecting hydraulic lines, a job that is commonly done by anyone comfortable rebuilding a trailer brake actuator, though a professional can also perform it.